$ git clone -n https://src.fedoraproject.org/rpms/goverlay.git /var/lib/mock/f41-build-836586-158875/root/chroot_tmpdir/scmroot/goverlay
Cloning into '/var/lib/mock/f41-build-836586-158875/root/chroot_tmpdir/scmroot/goverlay'...
$ git fetch origin ebf79e78bc5fe5fb618c2897c06cfed7965739d8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/goverlay
 * [new ref]         ebf79e78bc5fe5fb618c2897c06cfed7965739d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ebf79e7 Update to 1.2 upstream release